Integration of Ultra-short Chain PFAS into Routine Analysis Methods: Addressing Retention and Confirmatory Ions

Per- and Polyfluoroalkyl Substances (PFAS) in the Environment
Poster Presentation

Prepared by K. Organtini, S. Adams, D. Gordon, K. Whyatt, N. Meruva
Waters Corporation, 34 Maple St, Milford, MA, 01757, United States


Contact Information: [email protected]; 508-482-3242

ABSTRACT

The emerging problem of environmental and health hazards of long chain (≥C8) PFAS meant many have been substituted for short and ultra-short chain PFAS. This has led to the analytical requirement to analyze ultra-short chain PFAS in the same methods developed and applied for longer chain PFAS. This is challenging not only in terms of a suitable chromatographic method that will retain this set of compounds but also in terms of ion ratio identification of shorter chain length PFAS, such as PFPrA and PFBA, due to the limited mass fragments generated. Both challenges are addressed in this work. The ultra-short chain PFAS were chromatographically retained using a mixed mode column that uses both reverse phase and anion exchange retention mechanisms. Additional fragments for the ultra-short chain PFAS were evaluated using the m/z 19 fragment to provide a confirmatory ion for those that historically have not had one easily available by enhancing low mass transmission of the mass spectrometer. Using these settings, a there was an observed increase in the response from the m/z 19 fragment of 6 times for PFPrA, 17 times for PFBA and 30 times for PFPeA, compared to the response using the standard settings. By using a mixed mode separation column and tandem mass spectrometer with automatically applied low mass transmission settings this can be overcome without compromising the performance for other PFAS.